The present invention relates to a switchgear cabinet comprising a closed housing and a cooling device for cooling electrical and/or electronic equipment that can be disposed inside the housing.
Electrical and electronic components of a process plant, a machine tool or production device which are not located directly in the machine (e.g. sensors) are accommodated in a separate housing for several reasons. The housing is designed to protect the components accommodated therein from, among other things, dust and water, to serve as a means of supporting and structuring the internal layout and of protecting the equipment accommodated therein from overheating, etc.
However, in the case of housing designs for high protection categories, e.g. for IP 54 or IP 65, or for outdoor applications, particular measures are required for cooling the equipment disposed in the housing.
Thus, in the case of air-cooled housings for high protection categories, filter devices for the cooling air, such as e.g. filter mats disposed in the air flow, are provided. This can provide protection up to IP 54. However, the disadvantage of this is that the filters must be regularly cleaned or replaced.
For outdoor applications, so-called push-through cooling is also used whereby equipment with high thermal power loss, such as e.g. semiconductor power modules, are cooled directly using ambient air. The push-through cooling comprises a heat sink disposed in a housing wall. The item of equipment is mounted on the heat sink inside the housing, the cooling fins of the heat sink are disposed outside the housing. The heat sink must be designed for “dirty” air which necessitates wider cooling fin spacings and therefore correspondingly large sizing of the heat sink. In addition, heat sink cleaning can be difficult depending on the housing's mounting location and environment. The heat of operation of the other items of equipment disposed in the housing must then be additionally dissipated e.g. via air cooling using filter mats disposed in the air flow.
High thermal power losses of the equipment disposed in the housing can also be dissipated via liquid cooling. However, a liquid cooling circuit, e.g. a water circulation, for cooling is only available in a small number of applications.
Lastly, air conditioners are used to cool the equipment disposed in the housing. However, air conditioners must be maintained, e.g. to change the filters, and require additional energy for operation.
US patent application publication US 2015/0217829 A1 describes a cooling device of flat design for computers or other electronic devices, said cooling device operating according to the thermosiphon principle. The thermosiphon cooling device is disposed in a computer housing together with a heat source to be cooled, typically a CPU (Central Processing Unit), and comprises an evaporator placed on top of the heat source and a condenser disposed horizontally beside it. The condenser has cooling fins which dissipate the heat to an air flow. After passing through the cooling fins, the air flow can leave the housing via exhaust vents.
US patent application publication US 2014/0090814 A1 describes a thermosiphon cooling device for an electronic device. In the application, the thermosiphon cooling device is incorporated in a server enclosure with the semiconductor components to be cooled, in this case CPUs, and other components. A condenser associated with the thermosiphon cooling device is disposed inside the server enclosure in an air duct such that it can be externally supplied with cooling air by means of fans.
PCT publication WO 2008/108777 A1 likewise discloses a thermosiphon cooling system of flat design for an electronic device, said cooling system being accommodated in a housing together with the heat generating components. Holes are provided in the housing on two opposite flat sides. Fans produce an air flow which dissipates the heat generated by the components from the housing.
German utility model specification DE 20 2012 008 740 U1 describes a cooling system for power electronic converters, having a primary cooling flow for cooling a secondary cooling circuit via heat exchangers. The secondary cooling circuit is connected in a thermally conductive manner to power electronic components and implemented as a thermosiphon cooling circuit. At least some of the heat exchangers are redundant so that they can be replaced by another heat exchanger of the same type without interrupting operation.
The object of the present invention is to specify a switchgear cabinet comprising a closed housing and a robust and low-maintenance cooling device for cooling electrical and/or electronic equipment that can be disposed in the housing.